2, 5-bis(phthalimidomethyl)-tetrahydrofuran



useful as. an intermediate to produce United States Patent2,5-BIS(PHTHALIIVIIDOMETHYL)- TETRAHYDROFURAN Arthur C. Cope, Belmont,Mass.

No Drawing. Original application February 27, 1956, Serial No. 567,725.Divided and this application March 20, 1957, Serial No. 647,212

1 Claim. (Cl. 260-326) This invention relates to the compound 2,5-bis(phthalimidomethyl)-tetrahydrofuran which has the following structure:

1? i \N-CH)L JVCHPN/ 0 l l The starting compound for making this productin accordance with this invention iscis-2,5-bis-(hydroxymethyl)-tetrahydrofuran ditosylate. This startingcompound is obtainable by the procedure outlined by F. H. Newth and L.F. Wiggins in the Journal of the Chemical Society, 155 (1948). Thecis-2,5-bis-(hydroxymethyD-tetrahydmfuran ditosylate is converted to2,5- bi's-(phthalimidomethyl) -tetrahydrofuran by reaction withpotassium phthalimide in the presence of dimethylformamide. Thismixtureis heated and after cooling the solution is poured into achloroform-water mixture. The chloroform layer is recovered and isWashed with sodium hydroxide. and water and then dried over sodiumsulphate and concentrated to a small volume. The solid that separates is2,5 bis (phthalimidomethyl)-tetrahydrofuran which may then berecrystallized from ethanol.

EXAMPLE I 2,5-bis- (phthalimidomethyl) -tetrahydr0furan A mixture of11.0 g. of cis-2,5-(hydroxymethyl)-tetrahydro'furan ditosylate, 10.0 g.of potassium phthalimide and 50 ml. of dimethylformamide was heated at155-165" for 16 hours. After cooling, the solution was poured into amixture of 100 ml. of chloroform and 150 ml. of water. The chloroformlayer was separated, washed with 2 N sodium hydroxide and water, driedover sodium sulphate and concentrated to a small volume. The solid thatseparated amounted to 4.5 g. (45%) of 2,5-bis-(phthalimidomethyl)-tetrahydrofuran.

i i" I l N-GHr- CHr-N .Q/ O 3..-

A ll The 12,5-bi's-(phthalimidomethyl)-tetrahydrofuran is thediamine..2,5-bis- (aminoxnethylJ-tetrahydrofuran.

which aftenarecrys'tallization from ethanol melted at 228- 2 EXAMPLE u2,5-bz's-(aminomethyl) -tetrahydrofuran A solution of 15.3 g. of2,5-bis-(phthalimidomethyl)- tetrahydrofuran and 5.0 ml. of hydrazinehydrate in ml. of methanol was heated under reflux for 2 hours. Themixture was cooled, 50 ml. of water was added, and the methanol wasdistilled under reduced pressure. Concentrated hydrochloric acid (50ml.) was added to the residue and the mixture was heated under refluxfor 1 hour. After cooling, the solid precipitate was separated and thefiltrate was. concentrated under reduced pressure. The residual solutionwas made basic with 2 N sodium hydroxide and extracted continuously withether for 2 days. The extract was driedover potassium hydroxide,concentrated, and the residue was fractionated through a semi-microcolumn, yielding 1.76 g. (35%) of 2,5-bis-(aminomethyl)-tetrahydrofuran.

B. P. 56 (0.26 mm.), N D, 1.4832. Analysis indicated that thishygroscopic diamine contained a small amount of water.

For analysis of the diamine, it was converted to the dipicrate by theaddition of the diamine to a saturated solution of picric acid inabsolute ethanol. The precipitate was separated and recrystallized fromethanol to a constant melting point of 211.5212.5

The 2,5-bis-(aminomethyl)-tetrahydrofuran is useful as a corrosioninhibitor. For example, it may beadded to boilers or radiators to reducethe usual corrosive action Which occurs therein. This diamine is alsouseful as an absorbent for acidic gases, such as CO S0 and H 8. Passageof a gas mixture containing such an acidic gas, through a column or bedof diamine will result in selective removal of the acidic gas.

This application is a division of my copending application Serial No.567,725, filed on February 27, 1956, and entitled2,5-bis(aminomethyl)-tetrahydrofuran.

I claim:

The compound, 2,5-bis-(phthalimidomethyl)-tetrahy- References Cited inthe file of this patent UNITED STATES PATENTS 2,452,315 Morgan et a1.Oct. 26, 1948 2,535,987 Randall et al Dec. 26, 1950 2,593,840 Buc Apr.22, 1952 2,835,714 Nixon et a1 May 20, 1958 OTHER REFERENCES Jour. Chem.Soc. (London), 1948, pages -158. Helv. Chimica Acta, vol. 37, #6, pp.1699-1706 (1954).

